期刊
ANALYTICAL CHEMISTRY
卷 82, 期 19, 页码 7965-7972出版社
AMER CHEMICAL SOC
DOI: 10.1021/ac101437w
关键词
-
资金
- NASA [NNG06GE79G, NNX09AE12G]
- NOAA
- NASA (NESSF) [NNX08AU77H]
- [NSF-ATM-0650023]
The aerosol direct effect, which characterizes the interaction of radiation with aerosol particles, remains poorly understood. By determining aerosol composition, shape, and internal structure, we can predict aerosol optical properties. In this study, we performed a feasibility study to determine if tapping-mode atomic force microscopy (TM-AFM) and Raman microscopy can be effectively used to obtain information on aerosol composition, shape, and structure. These techniques are advantageous because they operate under ambient pressure and temperature. We worked with model aerosol particles composed of organic components of varying solubility mixed with ammonium sulfate. In particular, we explored whether aerosols could be differentiated on the basis of the solubility of the organic component. We also characterized the aerosol internal structure and investigated how this structure changes as the solubility of the organic compound is varied. To obtain indirect chemical information from AFM, we imagedparticles supported on both polar, SiOx/Si(100), and nonpolar, highly ordered pyrolytic graphite, surfaces. We have found that AFM can be used to differentiate the solubility of the organic component. In some cases, AFM can also be used to identify internal structure. With Raman microscopy, we can differentiate between core-shell structures and homogeneous structures. Surprisingly, we find that even for the most soluble compounds, core-shell structures are observed. To discuss consequences of our results for climate studies, we calculate the difference in radiative forcing caused by having a core-shell aerosol rather than a homogeneous particle. Overall, these techniques are promising for characterizing composition, shape, and internal structure of atmospheric particles.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据